CVE-2026-102271

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Source
https://cve.org/CVERecord?id=CVE-2026-102271
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-102271.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-102271
Aliases
Downstream
Published
2026-09-28T20:31:53Z
Modified
2026-09-30T03:49:03Z
Severity
  • 7.4 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard
Details

PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because asymmetric-key guard relies on textual markers that are absent from DER encoding. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-347"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102271.json"
}
References

Affected packages

Git / github.com/jpadilla/pyjwt

Affected ranges

Type
GIT
Repo
https://github.com/jpadilla/pyjwt
Events
Introduced
83ff831a4d11190e3a0bed781da43f8d84352653
Fixed
2798504fa2663364573cf2d1043d8d7fef389499
Fixed
c6fe464b356ff4b1ebc9ba62172d331a40aa27df
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "2.4.0"
        },
        {
            "fixed": "2.14.0"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

2.*
2.10.0
2.10.1
2.11.0
2.12.0
2.12.1
2.13.0
2.4.0
2.5.0
2.6.0
2.7.0
2.8.0
2.9.0

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-102271.json"